We shall continue a variety of physical and chemical studies on bacterial virus structure and assembly. These include: a. Refine and scale up T4 tail fiber preparation. b. Use the tail fibers to investigate physical structure, similarities with myosin, and interactions with gp63, actin, and other possible actin-like proteins in baseplates. c. Elucidate mechanism of tail tube length determination and kinetics of tube polymerization, using normal, mutant, and proteolytically cleaved baseplate and tube proteins. We shall also continue investigations of soluble and insoluble classes of chromatin, focusing on structural and compositional differences. In the investigations, quasielastic laser light scattering and other hydrodynamic techniques will be primary tools.